Determinant quantum Monte Carlo study of -wave pairing in the plaquette Hubbard hamiltonian
We used the determinant Quantum Monte Carlo (DQMC) to determine the pairing and magnetic response for a Hubbard model built up from four-site clusters - a two-dimensional square lattice consisting of elemental 2x2 plaquettes with hopping t and on-site repulsion U coupled by an interplaquette hopping t' ≤ t. Superconductivity in this geometry has previously been studied by a variety of analytic and numeric methods, with differing conclusions concerning whether the pairing correlations and transition temperature are raised near half-filling by the inhomogeneous hopping or not. For U/t = 4, DQMC indicates an optimal t'/t ≈ 0.4 at which the pairing vertex is most attractive. We also found that optimal t'/t increases with U/t. We then contrast our results for this plaquette model with a Hamiltonian which instead involves a regular pattern of site energies whose large site energy limit is the three band CuO2 model; we show that there the inhomogeneity rapidly, and monotonically, suppresses pairing.
- Harbin Inst. of Technology (China). Dept. of Physics
- Pennsylvania State Univ., University Park, PA (United States). Physics Dept.; Univ. of California, Davis, CA (United States). Physics Dept.
- Federal Univ. of Rio de Janeiro (Brazil). Inst. of Physics
- Univ. of California, Davis, CA (United States). Physics Dept.
- Publication Date:
- OSTI Identifier:
- Grant/Contract Number:
- Accepted Manuscript
- Journal Name:
- Physical Review. B, Condensed Matter and Materials Physics
- Additional Journal Information:
- Journal Volume: 90; Journal Issue: 7; Journal ID: ISSN 1098-0121
- American Physical Society (APS)
- Research Org:
- Univ. of California, Davis, CA (United States)
- Sponsoring Org:
- USDOE National Nuclear Security Administration (NNSA)
- Country of Publication:
- United States
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
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